How to Build a Strong Trellis

Many plants grown in the garden, including grapes, kiwifruit and passionfruit, require a strong trellis of some kind to support the weight of the vines they produce, particularly when laden with fruit. The trellis also keeps fruit off the ground, away from excess moisture and pests, and makes it easier to harvest when ripe. A strong trellis with flowering plants, such as clematis, mandevillia or jasmine, can also provide an enduring accent to a patio area or yard. Building a trellis requires just a few materials and about a weekend to complete.

Things You'll Need

3 4-by-4 wooden posts, 10 feet long

6 2-by-6 wooden boards. 4 feet long

3-inch decking screws

Drill

Post hole digger

6 bags quick-dry cement

Carpenter's level

10 2-by-2 wooden boards, 8 feet long

Electric drill with Phillips screwdriver bit

Position the center of two of the 2-by-6-inch boards as crossbars on either side and at the end of one of the 4-by-4 posts to form a T shape. Screw the crossbars to the post with decking screws and a drill. Repeat this step to form two more T-bar posts.

Dig a hole 2 feet deep with the post hole digger. Insert the end of one of the T-bar posts in the hole. Align the T-bar post in the direction the trellis will run. Pour dry cement into the hole to fill it. Repeat this step with the other two T-bar posts at 6-foot intervals.

True each post with the carpenter's level, adjusting the post angle as necessary. Add water to the cement to wet it completely. Let the cement set over the next 24 hours.

Place two of the 2-by-2 boards across the top of the T-bar posts, end to end in the center of the T-bars, with the ends sticking out off both of the end T-bar posts. Screw the 2-by-2 boards in place on the crossbars with decking screws.

Place two more of the 2-by-2 boards across the top of the T-bar posts in the same manner as the first set of boards. Position the boards to one outside edge of the T-bars. Screw the 2-by-2 boards in place with decking screws. Repeat this step on the other side of the T-bars with two more 2-by-2 boards.

Place two 2-by-2 boards across the top of the T-bar posts between the outer 2-by-2 boards and the center 2-by-2 boards. Screw the 2-by-2 boards in place with decking screws. Repeat this step on the other side of the T-bars with two more 2-by-2 boards.

Tips & Warnings

To increase the longevity of your trellis, use pressure-treated lumber, or paint the wood with an outdoor stain or paint.

Plant your vines near the posts and train them up the posts and over the cross bars for the best possible support.